This invention relates generally to apparatus and methods for talking books having entertainment and educational value, and more particularly to an interactive talking book system which produces auditory content based on the identity of the page of the book open to the reader.
A number of systems have been developed to provide supplementary audio content to a reader of a book. For example, U.S. Pat. Nos. 4,884,974 (DeSmet), 4,990,092 (Cummings), 5,453,013 (Billings et al.), 5,631,883 (Li), 5,645,432 (Jessop), 5,707,240 (Haas et al.), 6,064,855 (Ho), 6,729,543 (Arons et al.), 6,865,367 and 7,010,261 (Kim et al.), and 6,763,995 and 7,111,774 (Song), describe systems for providing audio content to a reader of a book.
Disadvantageously, some of these systems rely on manual activation by the reader to signal the identity of the open page. A young child trying to read the book alone may not be able to activate the system properly so the beneficial effect is lost. Other page-detection systems automatically detect the current page, but are either unreliable or very expensive. Optical systems using ambient light and optical detectors require adequate external illumination and are easily confused by poor lighting, misaligned pages, or holding the book improperly which blocks the receivers. Optical systems using self-contained light sources are less vulnerable to variations in ambient lighting, but are still quite vulnerable to page misalignments and improper holding, as well as imposing greater power requirements for the multiple light sources. These limitations may not be a problem when sitting in a chair at a table, but when used for bedtime reading, or in a family car, or on a plane, or at an outdoor picnic, or in any number of other situations where a child may want to read their favorite books, these limitations significantly impair the experience for the child and parent. Additionally, optical detection systems generally require individual detectors for each page, significantly increasing the cost of the books.
Existing systems teaching the use of magnetic sensors do not address the problem of variability of magnetic field strength caused by temperature fluctuations. The strength of magnetic materials used to mark pages of a book can decrease significantly with a rise in temperature. Often the facility where such books are assembled, and hence where the detector is calibrated, may not be climate controlled. Detectors calibrated during cold winter months may be unreliable when used during hot summer months, and those calibrated during cold winter months may be unreliable when used in hot summer temperatures. Permanent magnets exhibit a temperature dependence in their magnetic field strength. Rubber magnets can lose 3% of their strength for a temperature increase of 20 degrees F. The temperature in a factory during assembly can vary wildly. In Southern China, where many of the world's consumer products are manufactured, a factory floor can easily be 100° F. or higher during the Spring, Summer, or Fall. Temperatures during winter can dip into the 60s. The ambient temperature at the time of use by the consumer/operator would likely be markedly different. Failure to compensate for temperature induced magnetic field strength variation causes a magnetic-based page detection system to perform poorly at temperatures which are warmer or cooler than those at which the detector is calibrated.
Two methods of temperature compensation may be usefully applied. First is temperature compensation applied during page calibration in the factory (hereinafter referred to as “factory compensation”). This generally affects the calibration table. A manufacturer can input the temperature during the initial calibration. Embedded software then uses the input temperature value to shift the calibration table to a standard temperature, such as standard room temperature of 77° F. (25° C.), which approximates the anticipated temperature for typical consumer usage.
A second method is compensation applied during operation based on a real-time temperature input from a temperature sensor, such as a thermistor, (hereinafter referred to as “real-time compensation”). Real-time compensation requires one extra saved value (along with the calibration table). This value is the temperature sensor value during factory calibration. During operation the temperature sensor value is read along with the magnetic sensor output value. The magnetic sensor output value is then adjusted using a gain-offset calculation that includes the current temperature value and the value from the factory calibration. This scales the current magnetic sensor output value for the temperature at which the calibration table was generated. One variation to this approach is to use the real-time temperature value at power-up to adjust the factory calibration values to the current temperature. Incorporating a temperature sensor, such as a thermistor, to measure the ambient temperature allows for compensation of a magnetic sensor output due to temperature. The ambient temperature may be used to adjust the values of the calibration data to increase or decrease the range of values expected as the book pages are opened and closed, or may be used to create new calibration data for the time of use. These two methods are not exclusive and can be applied in tandem or individually.
Alternatively, a simpler, but less accurate, calibration procedure can be applied to compensate for temperature which does not require a temperature sensor, where the book system includes a sensor to detect when the front cover is closed and the output of the magnetic sensor system is measured each time the front cover is closed, such that the resulting measurement is used to adjust the calibration data. The re-calibration procedure will automatically compensate for temperature-induced changes in magnetic field strength of the fixed magnets by shifting the entire calibration table based on the difference between the stored baseline output for a closed book and the current output for a closed book. This method may be less accurate because it assumes that the entire difference between the factory calibration point and the local measurement is due to temperature differences. However, the inaccuracy may be acceptable to achieve a lower manufacturing cost because this method does not require a temperature sensor.
In addition, over time the pages of an audio book may become worn and swell, such that the increased page thicknesses can make the magnetic detector unreliable for the pages most distant from the magnetic detector. Existing apparatus and methods are not capable of recalibrating for given temperature conditions and variations in the physical condition of the pages.
The existing art fails to provide page detection systems which are both inexpensive and can reliably determine which of the multiplicity of pages is open to the reader in a wide variety lighting and temperature conditions, and regardless of the condition of the pages. The public would be benefited by an inexpensive system that can reliably detect the identity of an open page of a book to provide auditory content based on the identity of the open page.
The following represents a list of known related art:
Reference:Issued to:Date of Issue:U.S. Pat. 7,111,774 B2SongSep. 26, 2006U.S. Pat. 6,763,995 B1SongJul. 20, 2004U.S. Pat. 4,884,974DeSmetDec. 5, 1989U.S. Pat. 4,990,092CummingsFeb. 5, 1991U.S. Pat. 5,453,013Billings et alSep. 26, 1995U.S. Pat. 5,631,883LiMay 20, 1997U.S. Pat. 5,645,432JessopJul. 8, 1997U.S. Pat 5,707,240Haas et alJan. 13, 1998U.S. Pat. 6,064,855HoMay 16, 2000U.S. Pat. 6,729,543 B1Arons et alMay 4, 2004U.S. Pat. 6,865,367Kim et alMar. 8, 2005U.S. Pat. 7,010,261 B2Kim et alMar. 7, 2006
The teachings of each of the above-listed citations (which does not itself incorporate essential material by reference) are herein incorporated by reference. None of the above inventions and patents, taken either singularly or in combination, is seen to describe the instant invention as claimed.
U.S. Pat. No. 4,884,974 to DeSmet teaches an optical page reader system using bar codes printed along an edge of each page and a mirror system to direct the image to an optical reader built into the book holder. No discussion of magnetic page detection methods or apparatus.
U.S. Pat. No. 4,990,092 to Cummings teaches the use of pressure switches arranged on the back end of the book holder. The pages include non-overlapping holes through them so that when a page is turned the pressure switches which are not aligned with the holes are depressed and the page can be determined. Also includes pressure switches arranged below the planes of the pages with corresponding holes through the pages so that a reader can push the buttons and interact with the book. No discussion of magnetic page detection methods or apparatus.
U.S. Pat. No. 5,453,013, to Billings et al, teaches an audio visual book with touchpad switches containing images or symbols matching images or symbols on the pages of the book which, when pressed, produce a sound corresponding to the symbol or graphic. For example, where the story indicates a dog barking, a symbol of a dog would be included on the page corresponding to a touchpad switch with a picture of a dog, and when the dog-switch is pressed the book produces the sound of a dog bark. Billings does not teach or disclose page detection systems, nor does it disclose the use of automatic generation of audio text corresponding to the page to which a book is turned.
U.S. Pat. No. 5,631,883 to Li teaches an audio book with a pressure sensitive conductive page indicator system and ROM module. No discussion of magnetic field sensors.
U.S. Pat. No. 5,645,432 to Jessop teaches electronic book device using pressure sensors and conductors, which must be pressed in a specified sequence for the device to read which page it is on. Jessop does not discuss magnetic sensors.
U.S. Pat. No. 5,707,240 to Haas et al. teaches the use of a plurality of magnets, wherein each page includes a single magnet which overlaps a corresponding magnetic sensor, including Hall effect sensors, on the back of the book holder, and wherein the page magnets do not overlap. Does not teach or address the use of a cumulative magnetic field. Haas discusses arranging the magnets throughout the plane of the page, along a single edge, and discusses use of magnetic sensors on both the front and back covers, as well as within the pages themselves with the magnets embedded in the front and back covers.
U.S. Pat. No. 6,064,855, to Ho, teaches an audio book with magnetic page detectors. Ho, col. 5, lines 39-56, FIG. 6. Uses a “plurality of magnetic field sensors” mounted to the book holder, with a corresponding plurality of “magnetic field generators” mounted to the edges of the pages—one pair corresponding to each page. The magnetic generators—i.e. tabs—do not overlap but are arranged along the page edges so as to not shield each other.
U.S. Pat. No. 6,729,543 to Arons et al. teaches a page detection and book identification system wherein the detector is an optical reader (ccd or scanner) which detects a barcode or other optical coding system printed on the pages using a mirror system. No discussion of magnetic detection.
U.S. Pat. No. 6,865,367 to Kim et al teaches the use of optical interference page detection systems only, using photosensors and holes through the pages. Kim mentions the use of hall sensors and discretely positioned magnets to provide page indications, but discourages this use as expensive because it requires the inclusion of magnets on each page. See Kim '367 at col. 2, lines 1-14.
U.S. Pat. No. 7,010,261 to Kim et al. teaches optical interference page detection systems only, using photosensors and holes through the pages.
U.S. Pat. No. 6,763,995 to Song teaches an electronic book reader system which utilizes magnetic switches, as opposed to field effect sensors. Each page requires an individual magnetic read switch which detects the polarity orientation of the magnet attached to the page.
U.S. Pat. No. 7,111,774 to Song teaches an electronic book reader system using “magnetic signatures” which are detected by “individualized reading elements”. The magnetic signatures are merely magnets with specified polarity arrangements and the individualized reading elements are merely reed switches. Each page requires an individual reed switch. Song '774 also discusses a cumulative magnetic field detection method, but does not disclose how such a method could be accomplished in the real world. Song '774 simply states that the system uses layering magnetic materials on top of each other and “magnetic sensors (such as a Hall effect sensors)” to determine how many pages are layered. The patent does not enable a person to make and use the claimed invention because it does not address the type of magnetic material, the method of calibrating the magnetic sensor, nor the effects of temperature variation on such systems—all of which are critical issues to make such a system work. Song '774 does not even address such issues.
Thus, while the foregoing body of art indicates it to be well known to have a book system with page detection for delivery of audio content, the art described above does not teach or suggest a book system with page detection which has the following combination of desirable features: (1) uses a single magnetic sensor and multiple magnets; (2) is inexpensive to manufacture; (3) is able to recalibrate the sensor for current conditions; (4) can reliably detect the correct page in any lighting condition; (5) can reliably detect the correct page in any temperature condition; (6) reliably detect the correct page even where the pages are worn and swollen; (7) can reliably detect the correct page without regard to how the book is held; (8) methods for providing such content reliably; and (9) methods for manufacturing such book systems.